Lightweight vehicle underframe



arch 2, 3.937a w. H. MUssEY ET A1. 2,072,804

LIGHTWEIGHT VEHICLE UNDER'FRAME originaLFiledgJune 17, 1953 1 R Y N L .Q 2mm M www m W E m m s T llllllllllllllxlll.

mmm H. BRTN P. BY'- arch 2, 1937. W, H MUSSEY ET AL 2,972,804

LIGHTWEIGHT VEHICLE UNDERFRAME riginal Filed June 17, 195s 3 Sheets-Sheet 2A w @ml m om RTM P. 151.0

Tur 1Q :2x-rosa 11111111111 -11.111111 1.1.1.1, Y B MQ QQ N WN www \\w\ A m3 1..H1.1U,1.H.||..1.H-

- 1 1 1 1 1.1 1111111111 R m1211111 111111 -www .1-51 11111111 W515i llwQ 1 @.3 Y www o o MM F|||Tl||||1l|1|||zlrlxl||lllx| I. l I I l |||f| l 1 l l |1||\ ons Wm W.Q\ MRO. \N%\ ANWNN NNN m hm am mm@ m :1Q m W 1! 13mm 1 Nm @Pm ,March 2, 1937., w. H. MussEY ET A1.

LIMGHTWEIGHT VEHICLE UNDERFRAHE 3 Sheets-Sheet 5 Original Filed June 17, 1935 H v,kvmmaui USSEY p. BLCDMBQ Patented Mar. 2., 1937 UNITED STATES PATENT OFFICE LIGHTWEIGHT VEHICLE UNDERFRAME Original application June 17, 1933, Serial No. 676,265. Divided and this application March 3l, 1934, Serial No. 718,446

3 Claims.

This application is a division of our copending application Serial No. 676,265, led June 1'7, 1933, for Light-weight railway car.

The invention relatesr generally to metallic railway car construction and more specifically to vehicles fabricated of aluminum or its alloys and has for its especial object the provision of a lightweight car underframe having strength equal to the much heavier constructions heretofore emplOyed.

The invention contemplates a railway car underframe incorporating the use of members so formed that they may readily be interlocked with and connected to associated members of the structure and adapted to receive other members of the assembly in such manner as to cause the underframe as a whole to act more nearly as a unit in transmitting stresses imposed.

Because of the sharp definition of contour obtainable in members formed by the extrusion process, it becomes practicable to unite a plurality of shaped members formed with interlocking faces and so disposed relatively that the assembled whole will present a structural element of such contour as to render it suitable for connection with associated members of the car framing.

In riveted aluminum structures involving the use of many pieces, the greatest uncertainty eX- ists with respect to the integrity of the joints between them. There is no assurance that the connected members will function in unison since the stresses imposed are usually transmitted from one member to the others by rivets, with the possibility that the metal about them will yield and the holes becomes elongated with ensuing deformation of the connected members due to their. low deflection value and the unequal stresses imposed. Therefore, the use of aluminum requires that the arrangement and location of parts be such as 40 properly to transmit the stresses set up, giving due regard to the distribution and interengagement of the mass of the connected parts.

A particular object of the invention is to provide a car underframe of maximum strength and 45 capacity and of minimum weight, utilizing extruded stress members of advantageous contour and proportion substantially to reduce the number of parts required for its fabrication, and to adapt such members to the contours of associated en- 50 gaging members of the car framing to reduce the number of joints in the assembly.

An important ob-ject is so to correlate and dispose the members entering into the underframe assembly that it may be fabricated separately in 55 the shop and the completed assembly connected at the erection location with complemental side and roof framing assemblies.

The foregoing and other objects are attained by the construction illustrated in the accompanying drawings, in which Figure 1 is a plan view of a portion of a railway car underframe constructed in accordance with the principles of this invention;

Figure 2 is a plan view of another portion of the underframe complemental to that shown in Figure l; f,

Figure 3 is a longitudinal section taken on the line 3 3 of Figure 1 showing the construction of the draft sills and bolster at one end of the underframe;

Figure 4 is a View similar to Figure 3 taken on the line 4 4 of Figure 2 showing the bolster and draft sill construction at the opposite end of lthe underframe;

Figure 5 is a section longitudinally of the underframe through one end sill and bolster taken on the line 5 5 of Figure 1 looking towards the adjacent side sill;

Figure 6 is a View similar to Figure 5 taken on the line 6 6 of Figure l looking towards the draft sill of the underframe;

Figure 7 is a side elevational view of one form of strut used to provide a connection between the center sill and crossbeams of the underframe;

Figure 8 is a transverse sectional View taken on the line 8 8 of Figure 1 showing the end sill construction and the connection of the center and draft sills to the buier casting;

Figure 9 is a fragmentary section taken on the line 9 9 of Figure 1 through the end sill transversely of the underframe and showing the connection thereof to the side sill;

Figure 10 is a staggered, transverse sectional View taken on the line lil-l0 of Figure l through the bolster showing the construction thereof in detail together with the side bearing braces and bolster center fillers;

Figure 11 is also a staggered, transverse sectional view taken on the line H Il of Figure 1 and showing the connection of the floor pans and crossbearers to the center and side sills;

Figure 12 is a sectional view taken transversely of the center sill on the line l2 l2 of Figure 2 and shows another form of oor support;

Figure 13 is a sectional View taken longitudinally of the underframe through the anti-telescoping plate at the rear of the underframe on the line l3 |3 of Figure 2;

Figure 14 is a sectional View taken on the line 4-14 of Figure 2 showing the connection of the side sills and end buifer casting; and

Figure 15 is a cross sectional view through a modified form of side sill construction.

In the drawings, I represents a car underframe the embodiment of which in Figures l and 2 is shown with its front end adapted for a vestibule and at its opposite or rear end shaped with its side sills 2| approaching each other and their ends joined by a buffer end casting 18 whereby this end of the underframe, in plan, would assume a parabola in contour and lend itself readily for assembly with a superstructure having a slipstream rear surface.

The underframe assembly l is adapted to support upon its respective side sills 2| a side frame assembly of which the member 32 forms the bottom chord longitudinal in such a manner that the respective assemblies may be fabricated separately and subsequently connected together with a roof assembly at the erection location. The sills are of extruded aluminum of general Z-formation and are shaped to provide a web portion |68, outwardly extending bottom ange 11| upon which the bottom chord 32 of the side wall assembly is supported. The inwardly? extending floor supporting ange |69 is an integral part of a separately formed oor seal member adapted to interlock with a shouldered, thickened edge portion on web |68 of the sill and hereinafter described. Upon the upper flanges |69 the usual sub-licor sheets 12 are provided for supporting the customary oor insulation and secured by rivets 13. Upon these sub-floor sheets 12 is laid the usual nailing and spacing stringers for supporting the car floor 16.

The floor seal member is formed to interlock with the sill web to function as part of the side sill and to provide a combined clip attachment for inside nish and a cove moulding and support for the floor. For this purpose, the floor supporting flange portion |69 is formed with an upstanding, reversely oiset flange |13 providing an outer groove |12 for interlocking with and receiving the shouldered, thickened edge |10 or tongue portion on the sill web and an inner and relatively higher groove portion |14 to provide a receiving cove for the oor.

The upper edge of the offset ange |13 is formed with a downwardly and inwardly extending hook i'iange |15 designed to provide an anchorage clip for inside finish sheet 4| at the floor line having a rebent edge portion |16 hooked under the flange as best illustrated in Figure l0. The sill parts are further secured together and to adjacent side framing members by rivets |11 to insure at all times a proper working relation between the interlocking members. This adaptaltion will permit the connecting rivets |11, ex-

cept those taking the side posts, to be machine riveted before assembling with the side wall structure.

In Figure 15 is illustrated a modied form. of side sill construction, and, like the sill of the rst embodiment, illustrates a sill of extruded aluminum and of general Z-formation except that the inwardly extending top and bottom flanges and 1|] as well as the relatively wide outwardly projecting bottom flange 1| upon which the bottom chord 32 of the side wall assembly is supported, are all made integral therewith. The floor seal member in the modioation constitutes an angle member 14 secured to the side sill flange 69 and to the side wall framing posts (not shown) with its vertical flange projecting above the level of the floor 16 at the side wall and functions with the underlying horizontal flange to provide an air and moisture proof seal at the floor line.

In both embodiments the bottom chord angles 32 of the side wall assembly rest upon and are secured to respective outwardly extended sill flanges by rivets 9 hand-driven at the erection location.

The side sills 2l in the present embodiment extend from the body end sill 11 to the opposite end of the car and conform to the side wall contour and to the buffer end sill 18 at door frame I4 as indicated in Figures l and 2. In cars fitted with vestibules at both ends, the sills will extend in a single plane to end sills at both ends of the car. Except for the bending-in of the side sills at the curved, opposite end of the car beyond the body bolster at that end and the elimination of end sill 11 and the vestibule, the underframe on opposite sides of the transverse center thereof is of substantially the same construction.

The interlocking feature between stress members of extruded aluminum shapes as represented in the interengagement of the side sill members |68 and |13 illustrated in Figures 8 to 1l inclusive may be extended to other of the stress transmitting members of the underframe if so desired. Within the scope of the invention, it is contemplated to incorporate extruded metal parts in the fabrication of bolsters, crossbearers and center sills where feasible and in combination with rolled plate members or extruded or pressed as suggested bythe intermediate member |82 of the strut assembly. As above, described, the flange |13 of the oor seal member forming one part of the side sill assembly is formed on its outer face with a groove |12 having a plurality of shoulders at its upper and lower margins adapted to receive between them corresponding shoulders on complemental tongue portion |10 projecting from the inner face of web |68 of the side sill member 2|.

To insure complete interengagement of the parts, the ange |13 of the seal member and web |68 of the sill are held together preferably by rivets |11 extending through the tongue or rib portion |18 and the groove |12, so that the metal of the rib will tend to ll the groove under pressure of vthe riveting operation to effect positive interlocking of the several members and virtual integration of the assembly, whereby the rivets will be relieved of shearing stresses to which they wouldlotherwise be subjected in joints depending on rivets alone to transmit the loads from one to another of the'assembly members, and the whole structure appreciably rigidified. Similar provision may readily be made for the interlocking of other framing member assemblies inY the underframe structure.

It will be noted that the total amount of metal comprising the different side sill assemblies is well balanced about a neutral axis respectively thereof. In Figure l5, the inwardly extending upper flange 69 of the side sill is made heavier than the lower inwardly and outwardly projecting anges 10 and 1| combined in order to bal-v ance the sill metal about a neutral axis intersecting the sill web 68 substantially midway of the upper and lower faces of the sill. The sills being -formed by the extrusion process may be shaped as required for connection with or accommodation of any associated part or fitting. As shown in Figure 15, the ends of holsters, iioor beams, crossbearers and the end sills may all of them severally CII be received between the respective upper and lower flanges 69 and l0 of the side sill.

The center sill construction is fashioned somewhat on the order of that covered in Patent No. 1,804,428 issued May l2, 1931, to W. H. Mussey, for car underframe construction, but differs materially therefrom in structure presently to be described. As in the prior patent, the top chords 'I9 and bottom chords 80 of the center sill are channel-shaped with their flanges 8| bent laterally to provide horizontal securing flanges 82, the channels respectively opening upwardly and downwardly.

Between the bolsters the center sill chords are spaced apart by crossbearers 8S and struts 84 and between the crossbearers and vestibule by pressed channel draft sill members 85 secured to and extending from the crossbearers 53 at their deepest point and tapering to the body bolsters 85 through which to the vestibule the height of such members remains uniform. The bottom chord between crossbearer S3 and a like crossbearer at the other end of the underframe is straight, and, in the present embodiment, slopes upwardly from said crossbearer to the bolster 85, then straight through the bolster to points intermediate the respective bolsters and end sills 7l'. The top chords T9, however, extend to points beyond the end sills for Yconnection with inwardly extending buffer housing portions 8l of the buffer end sill castings i8 supported upon the pressed channel draft sill members 85 which extend to the buer end sill and are secured to it.

Between the draft sills, the buffer cushion housing portion of the buffer casting is inserted with its side walls 88 secured by rivets 89 to webs 90 of the draft sills. Projecting outwardly from the upper edges of the housing side walls are supporting wings 9| overlying the draft sill top flanges 92 and secured thereto by rivets 93, the flange riveting area being depressed below the normal top face of the wings so that at the vestibule end the rivet heads will not interfere with the normal placement of the usual sectional platform plate 91% extending between and secured to the step risers 95 by rivets 9S and to the buffer wings by screws 9'? to permit removal of the intermediate section of the platform plate for access to the buffer housing 87.

The buffer casting wings 9| extend rearwardly toward the end sill 'i1 and unite back of the housing portion 8l' to provide connection webs for the ends of the center sill top chord 79. Thewebs conform to the contour of the sill chord and provide a major portion 98 secured to the webs 99 of the top chords between the flanges 8| and portions |00 in a higher plane for engagement with and connection to adjacent top chord flanges 82.

At the tapering rear end of the underframe the buffer casting 18 is adapted to receive the inwardly bent side sills 2| in pockets 254 shaped to conform to the curve of said sills and provide interlocking engagement therewith, whereby displacement of such parts during impact is prevented and maintenance of the original contour of the end insured during normal stressing of the structure. As best shown in Figure 14, the members |14 of the side sill structure rest upon and are secured by rivets 255 to wings 9| of the buffer casting I8 while the side sill members |58, interlocked with the members ll, extend downwardly along the adjacent side wall of the side sill pockets 25d and their outwardly extending bottom flanges l'll secured to the bottom of said pockets by rivets 256. Bottom chord longitudinale 32 of the side wall girders 26 are also secured to the bottom of the pockets 254 by the rivets 256 and to the outer side walls thereof by rivets 251. Buffer end sill wing members 258 extend from the buier casting 18 along the curved opposite sides of the underframe and are secured by rivets 259 and 260 to girder stiffening members 26 The buifer castings 18 at the ends of the underframe are substantially the same and each provided with a plurality of pockets 253 for the interlocking reception of vertical, anti-telescoping posts 249 forming a part of the superstructure to be mounted on the underframe.

As indicated in Figure 10, the pressed draft sills 85 have their upper and lower flanges 92 and |0| secured to and between outwardly extending ilanges 82 of respectively adjacent sill chord flanges 8| to form with such chords a box girder sill portion framed into the bolsters and extending to adjacent crossbearers 83 to provide a rugged column having open channel faces upon all of its sides. The bottom channel face is adapted to receive a center bearing plate I9 beneath the web 99 of the bottom chord 80 at the bolsters 86.

The side channel faces receive the strut members 84| and inner ends of bolster diaphragms |03 and floor pans |2l, and the upper channel face receives the nested portion 93 of the buer end insuring thereby a balanced transmission of f1 builng forces through the transverse members to the car sides. The center sill between the crossbearers 83 is open and the top and bottom chords at that section are tied together by struts S4 and intermediate crossbearers |2 since the sill chords at this point are parallel to the lines of impact and require only that they be held in alignment. In Figure l2 is shown a modification of the floor pan |2| of Figure 11 for use intermediate the crossbearers 83, and comprises a continuous channel-shaped pan ||3 extending transversely of the underframe and connected at its ends to each of the respectively opposite side sills 2 At the center sill position the pan is depressed as at lill to pass immediately beneath the center sill top chord 'F9 to the web 99 oi which it is secured by rivets l I5 and to the adjacent sill chord spacing struts 84 by rivets |88.

The bolsters 86 comprise each the diaphragms |63 placed back to back and extending between the center and side sills, the sills and diaphragms being connected by a top cover plate |04 extending from side to side and bolster to bolster to provide a unitary assembly. The undersides of the bolsters are covered by separate compression plates |05 extending beneath and tying together the sills and diaphragms and tted at their respective opposite ends with jacking pads |06 secured to the plates and adjacent side sills by rivets |01. 'Ihe holsters 89 adjacent their ends are further united and braced by hollov.r side bearing beams |08 connected to the holsters by angle clips |09 secured to the webs of diaphragms |03 and side walls l l0 of the beams.

The beams are preferably channel-shaped with their side walls flanged outwardly at for connection with the bolster top cover plate |04 to form therewith a box girder construction providing a rigid column for distributing shocks of impact and substantially reinforcing the bolster assembly, the outer flanges of the beams being spaced from adjacent margins of the top cover plate to secure upper flanges |89 of the side sills between them for a more complete integration of the underframe elements in the bolster area.

The structure at the bolster position is further strengthened against possible distortion of the cover plates |88 above the center sill. The top cover plates 84 normally function in tension, but when the car is supported upon jacks at the jacking pads |85 at the ends of the bolsters, they are placed in compression. Therefore, to prevent buckling of the cover plates, top and bottom, at the point where they bridge the upper and lower troughs of the center sill, suitable filler blocks |18 are inserted fore and aft of the plates between the plates and webs 83 of the top and bottom chords i8 and 88, as best shown in Figures 3, 4, and l0, and secured to both plates by the several rivets |78 to insure proper transmission of the stresses thus imposed.

At the bolster diaphragm positions, the draft sills 85 and center sill top and bottom chords '|9 and 88 are further held in proper spaced relation by bolster ller pans E88 secured to Webs 98 of the draft sills and webs 9S of the sill chords. The rivets |8 l, securing the pans to the top chord web, also connect the respectively adjacent filler blocks H8 to the sill, as indicated in Figure 10.

For the purpose of rigidifying the bolster assembly at the center bearing position, a bearing filler block 288 is inserted between the sill chord webs 88 and formed with a tubular pin bearing 28E for a king pin (not shown), the bearing having an extended lower portion 283 projected through the lower sill web for interlocking engagement with the body center bearing plate I8 nested within the lower chord channel of the center sill and secured to web 99 and lower portion cf the filler by rivets l l5, the ller block on its upper side being secured to adjacent top chord web 89 by rivets il?, the top cover plate |04 and both sill webs having openings registering with the tubular bearing 28| for reception of the king pin. A king pin keeper 2&5 extends through cover plate |84 into engagement with top chord web 29 and is secured in any suitable fashion,

In the form illustrated in Figure 10, the body center bearing plate is provided with a filler block and sill reenforcing portion 282 nested within the lower face of the center sill and shaped with a socket portion 285 in its upper face to receive the projected sleeve portion 203 of the king pin bearing 2M on the bolster filler block 208. Beneath the socket 285, the center plate is formed with a tubular portion 288 extending downwardly below the base of the plate to provide a second projection 287 for swiveling engagement with the center bearing plate supported upon the truck bolster (not shown) The body center bearing plate I8 is further provided with an annular depending flange portion 258 in concentric relation to the sleeve projection 28'? and dening between them a swivel 7 bearing portion 2|8 for the reception of a complemental, upstanding bearing portion on the truck center bearing plate.

The struts 84, as indicated in Figure 7, comprise each an open channel intermediate sec- H tion |82 and yopen top and bottom connections,

all preferably of extruded metal, but the struts as a whole may be unitary, pressed pan members as to all of their parts, as shown in Figures 6 and 10 to 12 inclusive, if desired. The top and botr tom connections are similar in form, each provided with spaced flanges |83 projecting from the base portion of the connection and assembled with the intermediate channel sections |82 with their respective flanges between and in overlapping engagement with the channel anges |86 to which they are secured to complete theV strut structure as by rivets |81, the assembled units 84 being secured to adjacent top and bottom sill flanges 82 through the medium of base plate portions |84 of the strut connections. These struts serve also to connect the various floor pans |2| and crossbearers ||2 to the center sill by means of rivets |88 taking one or the other of strut channel flanges |86 as indicated in Figure '7.

The end sill comprises, in the present embodiment, a continuous antitelescoping plate portion 22| extending between and secured to the inwardly projecting upper flanges |69 of the side sills, a pair of U-shaped transverse members having base plate portions 222 and front and rear upstanding flanges 223 and 224, respectively, extending from opposite sides of the center sill to the side sills 2|. The rear flanges 224 are bent rearwardly along their upper margins to provide attaching and supporting iianges 225 for adjacent edge of the antitelescoping plate 22| which bridges the gap between the flanges 225 across the center sill and connects the U-shaped members to unify the end sill assembly. These members are further reinforced transversely of the car by continuous angular members 226 secured to the upper side of the antitelescoping plate 22| to which and the underlying support ing flanges 225 they are secured by rivets 227|, as best shown in Figures and 6. The antitelescoping end sill plate 22| is further stiffened along its rear margin by flanges |89 extending transversely of the car between center and side sills and between side walls 8| of the center sill top chord 79.

The U-shaped members are connected to the draft sills 85 by connections 228 or otherwise and connected at their opposite ends to the side sills through the medium of angle connections 234 and the upstanding flanged portion 235 of the base plate 222. The U-shaped members are further stiffened by underlying cover plates 229 secured to base plates 222 of the members and preferably extending from the draft sills 85 to the side sills. These cover plates are of substantial width and formed with downwardly extending flanges 238 at their inner ends for connection to the draft sills and secured to the underside of outwardly projecting lower flanges of the side sills by rivets 23| whereby such plates would functionas gussets to preserve the rectangular relation between end sill and draft and side sills although separate gussets at draft and side sill positions Would meet the requirements in cases Where the intermediate portions of the end sill members thus connected do not require the reinforcement afforded by the extended cover plates shown. It will be noted that, as shown in Figures 5 and 6, the U-shaped members are indicated as opening upwardly, and in practice the car body end wall framing members (not shown) will all of them be framed into the end sill with their respective lower ends between the upstanding front and rear flanges 223 and 224 of the U-shaped members.

The anti-telescoping plate construction at the opposite or rear end of the underframe comprises, as illustrated in Figures 2 and 13, the continuous plate 22| extending between and secured to the respectively opposite side sills, underlying cover plates 229, having the downwardly extending anges 239 at their inner ends for connection to the draft sills, and extending between and connecting said draft sills and the respective side sills as in the end sill construction 11 at the opposte end of the underframe. Channel members 231, connecting the top and bottom cover plates, are substituted for the U-shaped transverse members of the end sill 11 and attached to the draft sills by angle connections 238 and to the side sills.

The anti-telescoping plate 22! is stiiened along its rear margin by flanges |89 extending transversely of the underframe between the center and side sills. The channel member 231 and bottom cover plate 229, as indicated in Figure 13, are deiiected downwardly as at 239 to clear upper flanges 82 and 92 of the center and draft sills, respectively, in order that the necessary depth of said channel member 231 might be reduced to a minimum.

It will be noted that repeated reference has been made to extruded members forming the stress elements of the underframe structure. By that designation it is intended herein to cover such members produced by the extrusion process which involves the method of forcing plastic metal under high pressure through a die having an aperture of the contour desired for the member to be formed, and references herein to such members made of aluminum are intended to embrace within the scope of the appended claims extruded metal shapes of metal other than aluminum and suitable for use in the extrusion process. As first above stated, the members produced by the extrusion method are characterized by accurately gaged dention of contour free from irregularities and practicable for interlocking connection with other members having like characteristics, whereby the number of parts in the assemblies where used is substantially reduced, with resultant saving in weight and cost of fabrication.

Conceivably, members having the requisite delineation of contour adapted for interlocking connection and produced by methods other than the extrusion process if obtainable within tolerances permissible in the interlocking relation as herein contemplated, whether aluminum or other metal, may be substituted for the extruded sections, if preferred- Due to the material saving in weight of the car as a result of the system of framing employed, the number and/or size of the axles of the supporting trucks may be substantially reduced.

What is claimed iszl. In an underframe for vehicles including center and side sill members, an end sill comprising a continuous antitelescoping plate portion extending between and connecting the side sills, a pair of U-shaped members having each a base plate portion with front and rear upstanding ilanges extending from opposite sides of the center sill to respectively adjacent side sills, connections between said last mentioned flanges and the antitelescoping plate and reenforcing plates underlying and secured to the base plates of the respective U-shaped members and to respectively adjacent center and side sills.

2. In an underframe for vehicles including center and side sill members, an end sill comprising a continuous antitelescoping plate portion extending between and connecting the side sills, a pair of U-shaped members having each a base plate portion with front and rear upstanding flanges extending from opposite sides of the center sill to respectively adjacent side sills, said rear flanges having bent marginal portions extending rearwardly in supporting engagement with adjacent edge of the antitelescoping plate, an angular reenforcing member extending continuously along said margin of the antitelescoping plate above the center sill for rigidly uniting said U-shaped members, and reinforcing plates underlying and secured to the respective U-shaped members and at their end portions to respectively adjacent center and side sills.

3. In an underframe for vehicles including center and side sill members, an end sill comprising a continuous antitelescoping plate portion extending between and connecting said sills, a continuous reenforcing member overlying the forward margin of said plate, reenforcing members at the rear margin of and underlying said plate between center and side sills, a pair of U-shaped members having each a base plate portion with front and rear upstanding flanges spaced apart to receive end wall framing members and extending from opposite sides of the center sill to respectively adjacent side sills, said rear flanges having bent marginal portions extending rearwardly in supporting engagement with adjacent forward edge of the antitelescoping plate, and reenforcing plates underlying and secured to the respective U-shaped members and at their end portions to respectively adjacent center and side sills and of substantially greater width than said U-shaped members to provide gusset connections with said sills.

WILLIAM H. MUSSEY. MARTIN P. BLOMBERG. 

